Tuesday

May 5, 2015

May 5, 2015

Total # Posts: 1,608

**Chemistry**

I have got the answer but can you explain me which formula you used after calculating q in part 1?
*December 15, 2014*

**Chemistry**

2C2H6+702---->4CO2+6H20 DELTAH= -3120.6 kJ/mol What mass of ethane must be combusted in order to heat 366 g of water from 25 degree celcius to 100 degree celcius? Assume the heat transfer is 100% efficient. a)44.1 g b) .903g c) 3.61g d) 2.21 g Should I approach this problem...
*December 15, 2014*

**AP Calc BC**

Solve the differential equation y'= radical(x)/(-3y) i made y' dy/dx and moved the y's to one side and the x's to the other, and ended up with y^2=(-4/9)x^3/2 + c, but i'm not sure if that's write, and is that the form i'm supposed to leave it in?
*December 15, 2014*

**AP Calc B/C**

The base of a solid is the region enclosed by y=x^3 and the x-axis on the interval [0,4]. Cross sections perpendicular to the x-axis are semicircles with diameter in the plain of the base. Write an integral that represents the volume of the solid. I drew a picture, but I ...
*December 15, 2014*

**Chemistry**

Got it. Thank you so much
*December 13, 2014*

**Chemistry**

Consider the thermal decomposition of potassium chlorate. 2 KClO3 (s)-----> 2 KCl (s) + 3 O2 (g) A mixture containing KCl and KClO3 weighing 1.80 g was heated producing 1.40 x 102 mL of O2 gas at STP. What percent of the original mixture was KClO3? Is this how I should ...
*December 13, 2014*

**chemistry**

Is the total pressure 1 atm because the questions says STP?
*December 13, 2014*

**chemistry**

I used PV=nRT for both the gases but I am not getting the right answer. Please help
*December 13, 2014*

**chemistry**

Suppose 100 mL of NO at STP is mixed with 400 mL of O2 at STP. 2 NO (g) + O2 (g)---> 2 NO2 (g) After the reaction goes to completion, what is the partial pressure of NO2 in the resulting mixture of gases at STP? I know the relation between pressure and volume is P1V1=P2V2, ...
*December 13, 2014*

**chemistry**

In the context of chemistry and the periodic table , periodicity refers to trends or recurring variations in element properties with increasing atomic number . Periodicity is caused by regular and predictable variations in element atomic structure .
*December 13, 2014*

**math **

what are two fractions both not positive who has a product of 5/8
*December 13, 2014*

**Math**

You have an ear infection and are told to take a 200 mg tablet of ampicillin (a common antibiotic) four times a day (every six hours). It is known that at the end of six hours, about 5% of the drug is still in the body. What quantity of the drug is in the body right after the ...
*December 12, 2014*

**chemistry**

Calculate the amount of heat required to heat a 4.0kg gold bar from 20∘C to 61∘C. Specific heat capacity of gold is 0.128 J/g∘C. How do we figure this out?
*December 12, 2014*

**English**

B C B B
*December 11, 2014*

**please help (algebra)**

What is the error and correction in finding the difference? 3/4 - 9/2 = 3 - 9/4 - 2 = (-6/2) = -3
*December 10, 2014*

**Math**

I mean $10.00 for every oil change
*December 10, 2014*

**Math**

jody gets paid $200.00 per week, plus $100.00 for every oil change she completes. write the equation that shoes the relationship between the number of oil changes and her weekly income. then write the slope of the line that represents the relationship
*December 10, 2014*

**language arts**

The answer is D
*December 10, 2014*

**Calculus**

Find critical points for y'=2/3x^3-4x
*December 8, 2014*

**language arts**

The answer is C
*December 7, 2014*

**Chemistry**

estimate Delta H for the following reaction C2H4 (g)+3O2(g)→2 CO2(g)+2 H2O(g) So we have (4) C-H bonds and (1) C=C bond or (H = 4*414 + 615= 2271) For oxygen, (3) O=O bonds or (H = 3*502=1506) 2CO2 is (2) O=C=O (H=730*4=2920) 2H2O is (2) H-O-H or (H=4*464=1856) Delta H...
*December 7, 2014*

**chemistry**

6. Ligands approaching in a square planar pattern cause some orbitals to be raised in energy. How many orbitals are on the highest energy level? a. A) 1 b. B) 2 c. C) 3 d. D) 4 e. E) 5
*December 6, 2014*

**chemistry**

Conductivity experiments indicate that tetraamminedichloropalladium (IV) chloride is composed of 3 moles of ions per mole of compound. When silver nitrate solution is added to a solution of the palladium compound, 2 moles of silver chloride per mole of compound are ...
*December 6, 2014*

**Chemistry**

Consider the following data. DeltaHf (Na2O (s))=-414kJ/mol Delta H sublimation(Na)=109 kJ/mol I.E. (Na)=495 kJ/mol Bond Energy (O2) = 495 kJ/mol E.A. (O) = -141 kJ/mol E.A. (O -) = 878 kJ/mol Use this information to calculate the lattice energy of Na2O (s). So, we have the ...
*December 6, 2014*

**chemistry**

Consider the reaction: 2H2S(g)⇌2H2(g)+S2(g) An equilibrium mixture of this reaction at a certain temperature was found to have [H2S]= 0.542M , [H2]= 2.64×10−2M , and [S2]= 7.54×10−3M . What is the value of the equilibrium constant at this ...
*December 5, 2014*

**chemistry**

Write an equilibrium expression for each chemical equation involving one or more solid or liquid reactants or products. HCHO2(aq)+H2O(l)⇌H3O+(aq)+CHO−2(aq) Use A for [HCHO2], B for [H2O], C for [H3O+], D for [CHO−2].
*December 3, 2014*

**CHEMISTRY**

A solution with a pH of 7 has a [OH1-] of? 0M or 7M???????????????????
*December 3, 2014*

**chemistry**

7M??
*December 3, 2014*

**chemistry**

A solution with a pH of 7 has a [OH1-] of? 1 x 10-7 M?? Is that correct
*December 3, 2014*

**Physics**

The engine of an automobile develops 176 hp when rotating at a speed of 1340 rpm. What torque (in foot-pounds) does it deliver? I tried using some kinematic equations, but that didnt work at all. Then I tried doing something where I would take an integral, but then I dont know...
*December 3, 2014*

**Math**

How to check 4=-2(4.5p+25) so the answers both check out and equal each other?
*December 1, 2014*

**Calculus**

Find dy/dx if x^2+y^2=2xy A. x/(x-y) B. (y+x)/(y-x) C. 1 D. -x/y E. None of these
*November 30, 2014*

**AP calc**

. If f(x) = {x^2+3x-1, x<=2 and -3bx+3, x<2 , find the value of b in order for f to be continuous
*November 30, 2014*

**AP Calculus**

Find f'(x): f(x)=(x^2-3x)/x^2 A. 2x-3/x^2 B. 2x-3/2x C. 1-(3/x) D. 3/x^2 E. None of these I get confused on the simplifying part.
*November 30, 2014*

**Math**

Which of the expressions is not equivalent to 1/25? A. 5^3×5^-5 B. 5^-1×5^-1 C. 5^-3×5 D. 5^-2×5^4
*November 30, 2014*

**AP Calculus**

Find limit as x approaches 1 5/(x-1)^2 A. 0 B. Negative infinity C. 5/4 D. Infinity E. None of these
*November 30, 2014*

**Calculus**

If f(x)=x^2+1 and g(x)=2x-1, find d/dx[f'(g(x))] at x=1 A. 2 B. 6 C. 4 D. 0 E. None of these
*November 30, 2014*

**Calculus**

Which of the following describes the graph of y=|2x+6|? A. Only continuous B. Only differentiable C. Both A and B D. Not continuous, not differentiable E. Constant
*November 30, 2014*

**science**

please anyone helppppppppp
*November 25, 2014*

**science**

explain how mutations in dna affect the traits of an individual
*November 25, 2014*

**Math**

7b - 2 = 1b + 10
*November 25, 2014*

**chemistry**

The National Institute of Science and Technology (NIST) kinetics database lists the rate constant, k, of a particular gaseous reaction as 8.56× 10–10 cm3·molecule–1·s –1 at 298 K. convert to units of M-1 s-1. convert rate constant to units of...
*November 23, 2014*

**Math!**

2/3 × 3/5
*November 20, 2014*

**art**

Yes, the correct answer is A.
*November 20, 2014*

**Math**

Check for 2/3(k+8)=52
*November 19, 2014*

**Math**

-6(m+1)=24
*November 19, 2014*

**chemistry**

I figured it out! Thank you so much, I really do appreciate it.
*November 19, 2014*

**chemistry**

An ethylene glycol solution contains 18.2g of ethylene glycol (C2H6O2) in 85.4mL of water. Calculate the freezing point and boiling point of the solution. (Assume a density of 1.00 g/mL for water.)
*November 19, 2014*

**chemistry**

So would it be Delta T = i*Kf(0 degrees C)*1.40 Delta T/Kf *1.40v= i?
*November 19, 2014*

**chemistry**

Benzene is a carcinogenic (cancer-causing) compound. A benzene-contaminated water sample contains 3.1×10−5% benzene by mass. What volume of the water in liters contains 225mg of benzene? (Assume that the density of the solution is 1.0 g/mL.)
*November 19, 2014*

**statistics**

70% of 8 students would be 5.6, so estimate either 5 or 6
*November 18, 2014*

**calc**

Is the gradient of a function basically like the slope field. Also what is a conservative vector field. I know the definition but I'm having trouble visualizing it Thanks
*November 17, 2014*

**Math 6th**

Andy ran a 5-kilometer race in 40 minutes. If Andy maintains that same place, how many kilometers did Andy run In 1 hour?
*November 16, 2014*

**Social Studies HELP!!**

What can we infer from "they ought to get the sane treatment as Mr. Carlisle? What did Mr. Carlisle do? What was his treatment?
*November 13, 2014*

**chemistry**

A gas mixture is composed of 4.3 grams of hydrogen (density at STP = 0.089 g/L) and 2.9 grams of helium (density at STP = 0.179 g/L). What is the percentage (v/v) helium in the mixture? If v/v = Volume of gas/total volume how would we find the volume of both of the gases?
*November 13, 2014*

**chemistry**

Would the answer be .25596? 8.1/100= .081 .081*3.16= .25596
*November 13, 2014*

**chemistry**

How many liters of CO2 gas are contained in a 3.16 liters of a gas mixture which is 8.1% (v/v) CO2? They never gave us the formula or a process to figure this out in class. Will you please help?
*November 13, 2014*

**Physics**

How fast is an object traveling after 3seconds if its terminal velocity is about 35 m/s.?
*November 12, 2014*

**Physics**

What is the horizontal component of the force of an object sloped at a 45° angle. pulling with a force of 110N.
*November 12, 2014*

**Math**

The number of meters decreased by 25.6 is 84.3 meters.
*November 12, 2014*

**Math HELP!**

Please help me write an equation for these two: Ten fewer than the number of band instruments is 47 instruments. The number of meters decreased by 25.6 is 84.3 meters
*November 12, 2014*

**physics**

An unidentified flying object is cruising 30.0° north of east at a speed of 2132 km/h. How fast is it moving to the north?
*November 12, 2014*

**Social Studies**

What did Samuel Adams and Paul Revere do in the Boston Massacre?
*November 10, 2014*

**Math**

a lab has two bacterial cultures. culture a contains 8×10^4 bacteria and culture B contains 4 × 10^6 bacteria. How do the two cultures compare in size?
*November 10, 2014*

**Math**

Choose a number. Multiply by 2. Add 6 to the product. Divide by 2. Then subtract 3. What is the answer? Repeat this process using two different numbers.
*November 9, 2014*

**physics**

A 2.7 kg object falls from a tower. It experiences 2.3 N of air resistance. What is the acceleration?
*November 8, 2014*

**algebra **

would multiplying 3 negative integers always equal a positive integer?
*November 7, 2014*

**math**

what about 3 negatives? would the product always be positive?
*November 6, 2014*

**math**

is a negative times a negative ALWAYS positive? or can it be negative as well?
*November 6, 2014*

**please help! algebra**

find the next two numbers in the pattern: -12, 60, -300, 1500
*November 5, 2014*

**Math**

X/4 + 7 = 3
*November 3, 2014*

**Math**

-1.4b + 10 = (-18)
*November 3, 2014*

**Math**

2/3y + 6 =15
*November 3, 2014*

**chemistry**

What is the volume occupied by 0.252mol of helium gas at 1.35atm and 305K ?
*October 31, 2014*

**chemistry**

A bag of potato chips contains 575mL of air at 25.0∘C and a pressure of 765mmHg . Assuming the bag does not break, what will be its volume at the top of a mountain where the pressure is 458mmHg and the temperature is 10.0∘C?
*October 31, 2014*

**chemistry**

Thank you. That helped a lot.
*October 31, 2014*

**chemistry**

A balloon contains 0.126mol of gas and has a volume of 2.78L. If an additional 7.0×10−2mol of gas is added to the balloon, what will its final volume be?
*October 31, 2014*

**chemistry**

Calculate the concentrations of all species in a 1.22 M Na2SO3 (sodium sulfite) solution. The ionization constants for sulfurous acid are Ka1 = 1.4× 10–2 M and Ka2 = 6.3× 10–8 M.
*October 30, 2014*

**Math**

How did the Proclamation of 1763 attempt to protect the Native American rights and land?
*October 28, 2014*

**Math**

The slowest mammal on Earth is the sloth. A sloth might move along a tree at a maximum rate of just 3 ^-1m each minute. At this rate, how long will it take a sloth to climb a tree that is 33 m tall?
*October 27, 2014*

**college algebra**

C(x)=.80+.33x
*October 27, 2014*

**Mr. Anonymous**

Max = (-5/3,0) Min = (0,0)
*October 24, 2014*

**Chemistry**

How many moles of ammonia are in 1.20E25 molecules of ammonia.
*October 23, 2014*

**French**

You can say "On dit X" (One could say X) or "Le mot est X" (The word is X)
*October 23, 2014*

**Math**

Write each expression using a single exponent. Xy^5 • x^3 y^7
*October 22, 2014*

**Physics**

The blades of a ceiling fan have a radius of 0.393 m and are rotating about a fixed axis with an angular velocity of +1.36 rad/s. When the switch on the fan is turned to a higher speed, the blades acquire an angular acceleration of 1.82 rad/s2. After 0.475 s have elapsed since...
*October 18, 2014*

**Physics**

A top is a toy that is made to spin on its pointed end by pulling on a string wrapped around the body of the top. The string has a length of 54 cm and is wound around the top at a spot where its radius is 2.2 cm. The thickness of the string is negligible. The top is initially ...
*October 18, 2014*

**Chemistry**

or rather were questions
*October 18, 2014*

**Chemistry**

1)What could have caused the impurity in the sodium hydroxide solution? 2)Why was it necessary to dilute the hydrochloric acid before carrying out the titration? This was a question from a titration practical in which we had to dilute HCL then use that along with 25cm3 of NaOH...
*October 18, 2014*

**Physics**

A floor polisher has a rotating disk that has an 11-cm radius. The disk rotates at a constant angular velocity of 1.1 rev/s and is covered with a soft material that does the polishing. An operator holds the polisher in one place for 43 s, in order to buff an especially scuffed...
*October 15, 2014*

**Math**

(-3) ^-4 5 ^-2 =?
*October 15, 2014*

**Math**

How to solve 2^-1/5^2 ?
*October 14, 2014*

**Math**

3^-2/n and 7ab^-2/3w .
*October 13, 2014*

**chemistry**

A 300mL solution was made by dissolving 5.0g of MgCl2 in water. What is its molarity?
*October 11, 2014*

**Algebra**

A person has 29 1/2 yards of material available to make doll outfits. Each outfit requires 3/4 yard of material. a: How many outfits can be made? b: How much material will be left over?
*October 11, 2014*

**Math**

Melanie has 84 muffins, which he needs to box up, 9 of which are blueberry, into dozens. How many boxes does she need?
*October 6, 2014*

**Math**

Tim has forty five books. Jason has forty two times more books than Tim. How many books does Jason have?
*October 6, 2014*

**SS**

New France is _____ of the Appalachian Mountains.
*October 5, 2014*

**statistics**

A poll asked 500 adults if they thought Ontario should produce more, less or maintain current production of ethanol. -160 people responded "more ethanol production" -136 people responded "less ethanol production" -155 people responded "maintain current...
*October 5, 2014*

**Physics**

Two satellites, A and B, are in different circular orbits about the earth. The orbital speed of satellite A is eighty-two times that of satellite B. Find the ratio (TA/TB) of the periods of the satellites.
*October 3, 2014*